Electronic Design

CMOS-Based Sensor Cuts Chip Count In Digital Still Cameras

In the past, designers of digital still cameras first selected a CCD sensor and then added the necessary companion chips. But doing so led to multiple-chip-count configurations. This hindered a compact design and made it impossible to produce a digital still camera with a price tag below the $500 to $700 range. Now, Conexant Systems has introduced a solution that's expected to reduce selling prices to $200 or less.

The key is the company's CX20450 1.3-megapixel CMOS image sensor. Since the device is CMOS, it lends itself to integrating the various drive, sampling, and analog-to-digital functions onto a single sensor chip. This not only shrinks the device count, but lowers cost, and reduces power consumption. Plus, it diminishes the overall size of the camera without any sacrifice to image quality or shot-to-shot performance.

Conexant also is introducing a companion high-performance reference design kit. Designated as the TR08-D001, this kit is based upon Conexant's digital still camera chip set. The set contains both the CX20450 sensor IC and the Conexant Raptor IIC digital camera pro-cessor. Providing superior processing speed, the Raptor IIC is a flexible, high-performance digital camera processor, customized for the CMOS sensors.

Images captured by this reference -design enable camera users to create standard 5-by-7 and 4-by-6-in. prints that are nearly indistinguishable from prints created on film. What's more, designers using this chip set will be able to support all of the features normally found exclusively in higher-priced digital still cameras. These include a shot-to-shot time of less than two seconds, an NTSC/PAL output, and simultaneous support for CompactFlash or SmartMedia storage.

Also offered is an image-processing time of approximately one second and an automatic exposure/automatic white balance optimized for the CX20450's JPEG compression (1280 by 1024, and 640 by 480 pixels). In addition, the reference design can be expanded to incorporate communications technologies, such as Bluetooth and embedded version 90/version 92 modems.

The reference design kit comes with a full set of documentation, supplying guidelines for minimizing the design cycle and hastening time to production. Image Ex-pert image-management software is included as well. The software includes powerful search and organizational tools that enable camera users to manage a large number of digital pictures.

Now available, the TR08-D001 kit costs $15,000. The CX20450 1.3-megapixel CMOS image sensor is priced at $42 each. In higher volumes, the price falls into the $20 range. Priced at approximately $35, the Conexant Raptor IIC costs under $20 in larger volumes.

Conexant Systems Inc., 4311 Jamboree Rd., P.O. Box C, Newport Beach CA, 92658; (949) 483-4600; Internet: www.conexant.com.

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